The present invention relates to an improved insufflation system for use in double contrast barium enema studies.
Barium enemas are used by radiologists to diagnose abnormalities of the colon. There are both single and double contrast studies. Presently the double contrast study is the more practiced form of barium enema study. In a double contrast barium enema, a barium sulfate suspension is delivered, transrectally, into the patient's colon. The suspension is delivered through the central lumen of a multi-lumen enema tip. The barium sulfate suspension is held in a plastic bag which is suspended above the patient on a pole. The barium flow is controlled with a hand activated tubing clamp located on a tube that couples the plastic bag to the enema tip.
In a double contrast study, barium sulfate suspension is delivered into the colon to coat the colon lining. The colon is a collapsible, sack-like structure. To better visualize the colon after delivery of the barium, air is delivered to the colon through a separate lumen in the enema tip. The barium coating on the walls of the colon provide radiopacity to the colon and the air serves to expand the colon. Together the barium and the air provide a clinically useful radiographic image.
As double contrast studies are presently performed, ambient air is delivered into the colon using a hand-held delivery bulb. One problem with double contrast barium enema studies is that the insufflated air distends the colon and this distention, along with gas cramps from the air, causes considerable patient discomfort which may continue for some hours after the procedure. This patient discomfort makes it more difficult to get patients to have barium enema studies when these studies are medically indicated. Since these studies are used to diagnose, among other things, colon cancer, it is imperative to get patients to have the study performed when needed.
It is known in the art that carbon dioxide can be used instead of air to perform a double contrast barium enema study. The use of carbon dioxide minimizes patient discomfort because carbon dioxide is absorbed by the body, through the colon, at a rate of about 150 times faster than air and thus both the distention and gas cramps are minimized.
Carbon dioxide, although better for patient comfort, presents certain problems. In order for carbon dioxide to be used in a radiology suite or hospital the carbon dioxide must be contained under considerable pressure. This allows a large volume of the gas to be held in a small space. The colon is a fragile structure which can be damaged if inflated to pressures in excess of 90 mmHg (less than 2 psi). If the pressurized carbon dioxide were directly coupled to a patient there would be considerable safety issues associated with possible over-insufflation of the colon and attendant damage thereto.
Accordingly it is an object of the present invention to provide a system for safely, inexpensively, and efficiently delivering carbon dioxide into a patient during a double contrast barium enema procedure.
Still another object of the present invention is to provide such a system where the high pressure carbon dioxide is functionally isolated from the patient.
A further object of this invention is to provide such a system where the system is relatively compact and portable.